Feat: message manage (#12083)

### What problem does this PR solve?

Message CRUD.

Issue #4213 

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

rag/prompts/generator.py

@@ -136,6 +136,19 @@ def kb_prompt(kbinfos, max_tokens, hash_id=False):
     return knowledges
 
 
+def memory_prompt(message_list, max_tokens):
+    used_token_count = 0
+    content_list = []
+    for message in message_list:
+        current_content_tokens = num_tokens_from_string(message["content"])
+        if used_token_count + current_content_tokens > max_tokens * 0.97:
+            logging.warning(f"Not all the retrieval into prompt: {len(content_list)}/{len(message_list)}")
+            break
+        content_list.append(message["content"])
+        used_token_count += current_content_tokens
+    return content_list
+
+
 CITATION_PROMPT_TEMPLATE = load_prompt("citation_prompt")
 CITATION_PLUS_TEMPLATE = load_prompt("citation_plus")
 CONTENT_TAGGING_PROMPT_TEMPLATE = load_prompt("content_tagging_prompt")